Pediatric Transthoracic Cardiac Vector Flow Imaging - A Preliminary Pictorial Study

Abstract

Purpose Conventional pediatric echocardiography is crucial for diagnosing congenital heart disease (CHD), but the technique is impaired by angle dependency. Vector flow imaging (VFI) is an angle-independent noninvasive ultrasound alternative for blood flow assessment and can assess complex flow patterns not visible on conventional Doppler ultrasound. Materials and Methods 12 healthy newborns and 3 infants with CHD were examined with transthoracic cardiac VFI using a conventional ultrasound scanner and a linear array. Results VFI examinations revealed common cardiac flow patterns among the healthy newborns, and flow changes among the infants with CHD not previously reported with conventional echocardiography. Conclusion For assessment of cardiac flow in the normal and diseased pediatric heart, VFI may provide additional information compared to conventional echocardiography and become a useful diagnostic tool.

Keywords: Cardiac flow; Congenital heart disease; Transthoracic echocardiography; Transverse Oscillation; Vector Flow Imaging.

Fig. 1

Blood flow in the right a and left b ventricle. Frames are recorded on two healthy newborns in apical four-chamber view. The direction and velocity of the blood flow are given by the corresponding color maps and indicated by the superimposed vector arrows. rv=right ventricle, lv=left ventricle.

Fig. 2

The flow in the pulmonary trunk a , the ascending aorta b , and aortic arch c of three healthy newborns. a and b are parasternal views, while c is a suprasternal view. Vortices behind the valves in the pulmonary trunk a and the ascending aorta b are marked with white arrows.

Fig. 3

Clockwise rotational flow in the ascending aorta a , and slow counter-clockwise rotational flow in the left ventricle b in short-axis parasternal views of two healthy newborns.

Fig. 4

Infant with a large VSD. Left-to-right shunt through a large VSD with reversed flow in the right ventricle a , and an increased sling-like flow in the left ventricle b . Frames are recorded in the apical view. The VSD is marked with a “star” in (a). rv=right ventricle, lv=left ventricle.

Fig. 5

Infant with ToF. a shows the right-to-left shunt through the VSD with reversed flow circulation in the right ventricle, and b shows the complex flow pattern in the pulmonary trunk due to pulmonary constriction. c shows increased clockwise rotation in the ascending aorta.

Fig. 6

Infant with coarctation of the aorta. Complex systolic flow in the descending aorta in an infant due to aortic narrowing a . After surgical removal of the constricted vessel segment, the flow complexity is reduced b . The frames are recorded in the suprasternal view. The coarctation is marked with an arrow in (a).